1. Field of the Invention
The invention relates in general to a data storage system and a data backup method thereof, and more particularly to a data storage system capable of backing up data in non-real time and a data backup method thereof.
2. Description of the Related Art
In modern society where the volume of information grows dramatically, whether important data or information can be properly preserved is highly valued by people. Thus, the data storage system with data backup function capable of completely preserving data has attracted consumers' attention.
At the same time, a conventional data storage system with backup function requires at least two independent storage devices (such as hard disc), wherein a storage device is used for storing original data, and the other storage device is used for storing backup data. Therefore, a cost of the conventional data storage system with backup function is too expensive. Besides, the conventional data storage system with backup function back ups data by way of backing up the entire original data regardless whether the data is important or not, hence decreasing the utility rate of the storage device. Also, the conventional data storage system back ups data under the real time backup mode (that is, the original data and the backup data are stored at the same time), hence deteriorating the transmission efficiency of the conventional data storage system.
Thus, how to effectively decrease the cost and increase the utility rate and availability of the data storage system without affecting the efficiency has become a focus in research and development of the data storage system.